import CanceledError from "../cancel/CanceledError.js";
import AxiosError from "../core/AxiosError.js";

const composeSignals = (signals, timeout) => {
    let controller = new AbortController();

    let aborted;

    const onabort = function (cancel) {
        if (!aborted) {
            aborted = true;
            unsubscribe();
            const err = cancel instanceof Error ? cancel : this.reason;
            controller.abort(err instanceof AxiosError ? err : new CanceledError(err instanceof Error ? err.message : err));
        }
    }

    let timer = timeout && setTimeout(() => {
        onabort(new AxiosError(`timeout ${timeout} of ms exceeded`, AxiosError.ETIMEDOUT))
    }, timeout)

    const unsubscribe = () => {
        if (signals) {
            timer && clearTimeout(timer);
            timer = null;
            signals.forEach(signal => {
                signal &&
                (signal.removeEventListener ? signal.removeEventListener('abort', onabort) : signal.unsubscribe(onabort));
            });
            signals = null;
        }
    }

    signals.forEach((signal) => signal && signal.addEventListener && signal.addEventListener('abort', onabort));

    const {signal} = controller;

    signal.unsubscribe = unsubscribe;

    return [signal, () => {
        timer && clearTimeout(timer);
        timer = null;
    }];
}

export default composeSignals;
